Can We Really Tell Lossless From MP3?

EddieSpinola writes "Everyone knows that lossless codecs like FLAC produce better sounding music than lossy codecs like MP3. Well that's the theory anyway. The reality is that most of us can't tell the difference between MP3 and FLAC. In this quick and dirty test, a worrying preponderance of subjects rated the MP3 encodes higher than the FLAC files. Very interesting, if slightly disturbing reading!" Visiting with adblock and flashblock is highly recommended, lest you be blinded. The article is spread over 6 pages and there is no print version.

Comments

ABX Just Destroyed My Ego

[Snowblindeye]

Most people greatly overestimate how well they can hear these differences, but the never actually try it in ABX testing. I tried it years ago and I can't hear a difference between most codecs at reasonable bitrates and unencoded originals.

Here is an old classic from the Hydrogenaudio forums, from someone would bought expensive head phones and set up ABX testing. He was very shocked when he couldn't even tell the difference between FLAC and Vorbis at 64kb/s.

ABX Just Destroyed My Ego, My perception of my bitrate needs was greatly inflated.

Training and experience matter

[the eric conspiracy]

I've been exposed to people who write audio codecs for a living. They can tell because they've become sensitive to the artifacts present in MP3s. They also can pick up problems with CD's that haven't been dithered properly. They can easily pick out MP3 even at 320kbps. These are specialists. But even in this study there was one individual who had a high success rate.

At 192K and a good pair of headphones with good material I think most people could learn pretty quickly to pick up the difference - loss of stereo image at higher frequencies is pretty easy to pick up.

There are also studies available that point out the advantages of high bit rate recordings - these enable the use of sophisticated filters that eliminate some of the issues present with CD sound. If you are interested and have a mathematical bent, look up the work of Meridian's Peter Craven. Again the differences can be detected by specialists. I'm old enough so that my ears are not good enough to pick up these improvements.

I rip to FLAC and convert for my portables because of these factors.

If you want to try some testing yourself visit hydrogenaudio. They have apps set up to do abx comparisons so you can test yourself.

Ya this was a horrible test

[Sycraft-fu]

One problem is the simple A/B and asking which people like better. Well that is fine if you are doing something like testing two compression formats to see which has a sound people prefer. That is not fine if the question can people tell the difference between compressed and uncompressed music. For that you need an ABX test. X is a reference uncompressed sample, A and B are randomized such that one is uncompressed, one is not. People are then asked to identify the one that is the same as X. A test like that lets you tell if people can hear a difference, regardless of if they like it or not.

Also there is another angle to why people might choose to use uncompressed music and that is if there is any additional processing (like equalization) planned for later. Psychoacoustic compression schemes can have problems when processed later. Reason being that they do rely on things like masking, in that because X is happening, we can't hear Y. However when the balance of the sound is altered, well then that isn't necessarily the case anymore.

How important is that? Probably not very in a lot of cases. However how important is storage space? Last I checked 1TB was under $100. Storage is cheap. There's not really a need to milk every last bit out of a file. FLAC'd discs are in the realm of 300MB for a full CD. Big deal. I'm got space to spare, so why not go lossless?

What it really comes down to is what is "good enough" really depends on the situation. Depends on the music (some kinds cause more trouble for encoders), the listener, the environment, storage constraints and so on. I mean 64k is good enough to recognize the music. A 64k AAC or WMA is fine, FM radio quality maybe, and even a 64k MP3 is listenable. Is there distortion over what was on the CD? Sure, but maybe it is good enough in some situations (like say you need to be able to transmit stereo audio on a single DS-0 channel).

I really don't like these tests that try to give the one magic rate is that is good enough for all situations. Especially when they use bad testing methodology.

Personally, I'm a fan of lossless compression because then there's just not any additional errors. I've got the space so why not eliminate potential problems?

Re:The hiss is where it hides

[Vectronic]

"I think that the choice of playback software or drivers can also affect fidelity of the sound."

Indeed, pick any two media players that don't use the same decoder, they will both sound slightly different. Plus most default to 16bit, when the media might be 24bit (including mp3), or 32bit for FLAC, and others.

Driver implementation matters as well, I use the same drivers for my audio card for Windows XP (which the drivers were designed for), and Win7, but they both sound different, Win7 is slightly softer sounding, in XP it sounds a bit more over-driven, can't really compare between Linux distros as they almost never use the same drivers, and I usually don't bother to play with it, if it has sound, that's good enough.

I think any "optimized for metal" sound in Linux might be due to a more direct interaction with the hardware, which is great if you have hardware to support it, not if it's generic.

Re:The hiss is where it hides

[EQ]

A $70 pair of SHURE earbuds has made all the difference in how I listen to music

Sorry, but no earbuds are worth $70. They are simply evil and will destroy your hearing. Get yourself some proper earphones, something that cups the ear and ventilates.

One word for you: Grado. Highly recommended and reviewed at audiophile places. The lower end models price out at about the same as those earbuds, but with a superior sound. I recommend the SR80 - probably the best headphones in the price range. See Grado Labs - a small company in Brooklyn that still makes their stuff in the US.

Disclaimer: I have no fiscal interest in Grado -- I just like their gear. I have owned a set of SR60 for over a decade, and I use my 4 year old SR80's at work. The SR-225 headphones I got for Christmas last year from my wife never leave the house - they are that good (And a bit pricey). These are the best sounding headsets I've ever owned or used.

Re:The hiss is where it hides

[Terrasque]

I think you're spot on with that guess. For example, Red Hot Chili Pepper's cd release of Stadium Arcadium have been especially critisized for being too compressed (a result of the loudness war. Someone at hometheaterforum.com forum created a comparison between the CD and the LP (which had a much better mastering) release of the album, where you can clearly see the difference.

Now, the norm for most music released now is to mangle it in that way. And the audience is used to hear it that way too. So mp3 compression adding more artifacts to it and removing tones, thus mangling the music further, might sound "better" for a lot of the audience, because that's what they're trained to hear.